import urllib

from google.appengine.ext import db
from google.appengine.api import users
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
import os
from google.appengine.ext.webapp import template


class Greeting(db.Model):
    """Models an individual Guestbook entry with an author, content, and date."""
    author = db.UserProperty()
    content = db.StringProperty(multiline=True)
    date = db.DateTimeProperty(auto_now_add=True)


def guestbook_key(guestbook_name=None):
    """Constructs a datastore key for a Guestbook entity with guestbook_name."""
    return db.Key.from_path('Guestbook', guestbook_name or 'default_guestbook')


class MainPage(webapp.RequestHandler):
    def get(self):
        guestbook_name = self.request.get('guestbook_name')
        greetings_query = Greeting.all().ancestor(guestbook_key(guestbook_name)).order('-date')
        greetings = greetings_query.fetch(10)

        if users.get_current_user():
            url = users.create_logout_url(self.request.uri)
            url_linktext = 'Logout'
        else:
            url = users.create_login_url(self.request.uri)
            url_linktext = 'Login'

        template_values = {
            'greetings': greetings,
            'url': url,
            'url_linktext': url_linktext,
        }

        path = os.path.join(os.path.dirname(__file__), 'pages/index.html')
        #path = os.path.join(os.path.dirname(__file__), 'templates/two_column.html')
        
        self.response.out.write(template.render(path, template_values))


class Guestbook(webapp.RequestHandler):
    def post(self):
        # We set the same parent key on the 'Greeting' to ensure each greeting is in
        # the same entity group. Queries across the single entity group will be
        # consistent. However, the write rate to a single entity group should
        # be limited to ~1/second.
        guestbook_name = self.request.get('guestbook_name')
        greeting = Greeting(parent=guestbook_key(guestbook_name))
    
        if users.get_current_user():
            greeting.author = users.get_current_user()
    
        greeting.content = self.request.get('content')
        greeting.put()
        self.redirect('/?' + urllib.urlencode({'guestbook_name': guestbook_name}))


application = webapp.WSGIApplication([
  ('/', MainPage),
  ('/sign', Guestbook)
], debug=True)


def main():
    run_wsgi_app(application)


if __name__ == '__main__':
    main()

